The manufacture of molded plastic articles using injection molding is common state of the art. Moreover it is known to make hollow molded articles in a manner that following introduction of the flowable plastic into the injection mold cavity, pressurized gas shall be applied that shall evacuate a portion of the flowable plastic from the mold cavity through the runner duct.
After it has been removed from the injection mold, the molded articles comprises two apertures leading to the mold cavity, one aperture being constituted by the gas nozzle and the other by the hollow duct in the sprue which must be severed from the molded article. If such a molded article must be processed further, in particular in electroplating equipment, to fitted with metal coating(s), said apertures must be mandatorily sealed. Sealing the gas intake aperture raises no problems because a specific, geometric structure is involved and therefore an appropriate stopper may be used. On the other hand problems are encountered with the other aperture. The latter case inevitably entails further processing steps to seal the hollow molded articles against fluid leakage.